GEOG 371 Midterm: midterm 2 review

• School: University of Illinois
• Department: Geography
• Course: GEOG 371
• Professor: S Mc Lafferty

Document Summary

2/21 network data node: rivers, examples of network data edge edge. Intersections = nodes: non-planar graph, edges do not have to cross at nodes, ex highway overpasses, airplane network. Characteristics of networks: global indicators, size, connectivity, complexity. Network connectivity for planar network: global indicator, gamma index, = e / emax = e / (3n-6, e = # of edges, n = # of nodes, higher value of gamma, network = more connected. If i(cid:374)de(cid:454) = (cid:1005) (cid:374)et(cid:449)ork is (cid:373)a(cid:454)i(cid:373)all(cid:455) (cid:272)o(cid:374)(cid:374)e(cid:272)ted. Geog 371 lecture notes: alpha index, measures # of circuits as a proportion of max # of circuits. 2: higher value (close to 1) = well connected network, alpha index = 0, alpha index = 1/3, alpha index = 2/3. Connectivity matrix: place 1 in table if i and j (nodes) are connected with edge, 0 if not connected. Index of accessibility: measures total network distance from node to all other nodes in network.